An anonymous reader writes: Saudi Aramco, the world's biggest oil producer, has resumed operating its main internal computer networks after a virus infected about 30,000 of its workstations in mid-August.

The group, calling itself the ‘Cutting Sword of Justice’, claimed to have hacked Aramco systems in several countries before sending a virus across 30,000 computers achieving a 75 percent infection rate of all the company’s systems. It refuted suggestions that a nation state was behind the attack.